Apparatus for testing telephone lines



April 2, 1946. F. J. CANNON ET AL APPARATUS FOR TESTING TELEPHONE LINES Filed Dec. 7; 1945 4 2 Sheets-Sheet 1 gig EJCdnnon '& 6,2.

IN VEN TORS A TTORNE Y GOOdlUi/Z l 4 Aprll 1946. F. J. CANNON ETAL 2,397,837 N I APPARATUS FOR TESTING TELEPHONE LINES Filed Dec. 7; 1945 2 Sheets-Sheet 2 Em MM;

IN VEN TORS EJCanfion &G.E.Goodwua/ 1' BY Ru 0 \MQ.

A TTO RNE Y Patented Apr. 2, 1946 rec STATES PATENT OFFICE Frank "Jess 'Canno'nfi Millbrae,=-and"'George' Ellis *Goodwin, San Anselmo, Calit, assign'ors to Amerlcan 'l-elcphone and Telegraph (lompany, z-a.:.corporation.orNew York .ApiilicationTDecember 7, 194,3,ZSsriaFNoifSISflM 7- Claims. Cl. 1%9.21-'Z5.11) f .fl his invention relatesto testingeapp-aratus and more A particularly to apparatus for. making linsulation tests onv conductors in a telephone plant.

It. istheNpractice to make periodic routinetests 'inza-telephone plantnto determin .whetheratheinsulationbi the lines -has .become .sufllciently .defectivehdue, for example, to iwetweather, to cause grounds or-shortsand hence cause trouble on the .lines. One-of vthe. objects of. the. arrange- .ments of theinvention is toprovide aportable set capable of-making routine-leakage tests with-great rapidity so that aagreat many lines connected to a telephone exchange can be tested-ma comparativelyshort time. Another. feature-otthe invention is to provide a testing. set thatflwill vindicate whetherthetrouble. consists of aground-or a short and-"will al's0= indioate whether the-ground, ifait exists; is-on the tip 'or ring sideof sthe line. Other -objects -andefeatures of the invention will appear more fully from the detailed descriptiontherecf :hereinattengi-ven.

."In. the iarrangementsof' the-.inventioma rapid voltmeter test of subscribers 1 lines is made-for short circuits or grounds :due to v defec-ti-ve ainsu-lationi by: slidingsa :shoe containing :a .number 'of metal reed contacts over the line terminalssof za-edistributing frame of a telephone exchange; A detachable flexible cable 'wouldzconnect the'shoe toithe test: circuit Whichcould be inclosedt-in-ia smallz cabinet designed to rest on a: step of the distributing frame rolling ladder. .The shoemight be equipped with a: stop 1 magnet which --would function whenva faulty line "was reached (Bo-stop themcvement of the' shoe 'so that the faulty line could 'be recognized. The F shoe might also 1 be :equipped with a small crank :or-motor "driven device for advancing? the: shoe 2 step-'by-step -.at -r-a constant" speed-. over-==the terminals of thewlines being tested.

lAs the shee advancesrone of: a: first: set' of its contacts :places .-a i:circuit -condition, I such .as tground;:on the sleeve of the line to be tested-and .operates its cut-ofirelay to remove battery-and ground from the line-provided .it is-not'busy. Other contacts of this firstwsetof contacts don- .nect a'rbattery through a high-resistance=-to the rin -side ofthe line andconnectu a ground through-ma; high resistance: to the tip side OF-the line. :The battery and-ground is placed-on the .line

advance of the line test inorderto chargethe line: to :thesamepolarity as the :test circuit-bat- -teiry. 'llhis-isin order toavoid-adine capacity discharge :intothe test circuit which would cause-1a .-.fa'-lse trouble indicationxif the-dine was =charged :reversed'-.1to: the test circuit battery. z-otherwords, the; line: is'"flrst. properly conditioned for the. application orth test current.

."As' the. shoe. continues to. move,. another set. of contacts i'w'ilhcomeinto contact with .the line. Thisset 61. contacts isconnected to. a testing relay. With. further, mouementofhthe shoe the charging battery. and,.grourid,-connected to. the. ring and tip of the line respectively,-will.be removed because the line has .been..properly. charged for the application .of l. the l. test .current. I'The second .,set of contacts isiasso'ciatd. withv a relay. "If. the line. is not .busyihis. relayvwill. operate. and will apply a testibatteryttoithe ring an'dhgroundto.v the tip, of thelline .over certainuones of thesecond. set of contactsand through .asecond relay. If aground onshort: existslonithe line,.current' from the test ;battery will operate thisesecond. relay which. in tumwill operatea visualsignal an audible signal .and thevstopamagnet. andstop the' forward move- :ment ot the shoe. 'lhetestmanwillnow throw a key. and connectithe test battery tothe ringof the linathrough.aavoltmeterand connect round to the: itiptofl the'eline. .Jllhe voltmeter will give. an .indicationrof. the-amount. of .leakage on the line. Tmdeter-mine.iithisisdue-to-a short or. a ground on the. ring the testma-n w-i-llnow operate another .key and remove-the ground connected to the tip. .Ifithe voltmeter: now:contim1es to functionhe-will .knowi-that thetrcubleiis not caused byia shortbut is caused by agroundon the ring.

Iftroublecsuch as ashortorha ground on th ring; existston theli-ne-a-nd the foregoing .actions .took e-place 5 the test.- .man -.aftercompleting his measurements of thetrouble-would now operate a releasakcy. This would release thestop magnet, v stop the audible alarm, extinguish the visual alarm andallow the shoeto advance again. Obviously; ifeno trouble, such as a short or a ring ground: existed, the shoe would continue its. ad- =vance.wi-thout the-operation. of the, release key.

Having-attested. the. line to determine lit a I short or a ground on the ring side of the line existed .it. .is-- now desirab1e =to. test the line to see: if a ,groundcn them-p sideofethefline exists. Accordingly; asuthashoe advances another set of contactstwillecome inscontactewithatheline and will connectaa battery through-enlargev resistance .to theatip; .-.'1 his.battery.is .placed onthe line in advance of thei-test to cha1,'ge .the-v tip to the same epolarity as the test battery to avoid .a capacity achargewr. discharge from .ialsely. operating the testing. apparatus.

AAsMthe {shoe continues .to moveeanother :setof .contacts will ,come intoe contactvwith the. vline. setofzconta'cts is-connected-te. a: testing relay.

operate a key and connect the test batterythrough a voltmeter tothe tip. The voltmeter W will give an indication of the amount of leakage on the line due to the ground.

When the test man now operates the release key the test set is returned to. normal and the shoe moves ahead to testother lines.

The invention may be more fully understood from the following description together with the,

accompanying drawings in the Figures 1', 2, 2',

3, 4, and 6 of which the invention is illustrated.

In Figure lis shown a circuit diagram of the testing set of the invention. Fig. 2 shows a view of the bottom of the shoe. Fig. '2' shows a side view of a portion of the shoe. Figs. 3, 9i, 5, and 6 illustrate the operation of the metal reed contacts 'on the bottom of the shoe 'as they move over the line terminals on the distributing frame. Similar reference characters have been used to denote like parts in all of the figures.

In Fig. 2 is shown the bottom part of the shoe. Two grooved supporting members I and 2 are shown which are joined together by the members 3 and 4. These grooved supporting member are adapted to slide over the terminals of lines'terminatin-g at a distributing frame. In order that the shoe may move over the line terminals at a uniform'rate it is provided with a small crank 5 which will operate a ratchet wheel 6 which will engage a set of the line terminals and move the shoe forward. The shoe is provided with four rows of contacts which might be of the metal reed type. As the shoe moves forward the contacts S1, S2, $3.54, S5 and Se would engage terminals connected to the sleeves of various lines. The contacts R1 and R2 would engage contacts connected to the ring conductors of the lines to be. tested. Contacts T1 T2, T3. and T4 would en- .gage contacts connected to the tip side of the contact s; will leave, the terminal on which it is resting and come into contact withcontact S2 before S2 leaves the terminal S. This is shown in Fig. 6. The action of the Rcontacts and T contacts would be substantially the same as the S contacts.

In Fig. 1 is shown a circuit diagram of the portable testing set of this invention. The contacts S1, etc., R1, etc., and T1 etc., are'shown in this circuit diagram but, as heretofore pointed out, they would be mounted on the bottom of the shoe. For the purpose of illustrating the invention a line L is shown which is to be tested. This line would have a sleeve contact S, a ring contact -R and'a tip contact T terminating at the distributing frame, and as the shoe moves forward various ones of the S, R and T contacts would progressively come into contact with the terminals S, R and T. As the shoe advances contact S1 will place a ground 8 on the sleeve terminal of the circuit L and this will operate the cut-off relay 9 which in turn will remove the battery and ground from the ring and tip sides of the line provided it is not busy. The contact'Ri will connect to the ring side of the line the conductor Iii which is connected through a high resistance to the battery I i. The contact T1 will connect to the tip of the line L the conductor I2 which is connected through a resistance to the ground l3. The battery H will be the same voltage as the test battery to be used later on. Accordingly, the battery will be connected to the ring of the line and ground will be connected to the tip of the line. This battery and ground is placed on the line in advance of the line test in order to charge the line to the same polarity as the test circuit are provided to prevent interference and false failure indications when theshoe encounters intercepted subscribers lines as will be pointed out hereinafter. The shoe and its contacts might be connected by a flexible cable 1 to the portable The shoe is equipped-with a stop testing set. V magnet 31 for stopping the shoe when trouble is encountered. This is shown in Fi 2'. The stop magnet would be mounted on the top side of the arrangements shown in Fig. 2. It would be provided with an armature 310 which, when the magnet operates, would drive a pin 3' between a set of line terminals and stop the forward progress of the shoe. Figs. 3, 4, 5 and 6 show the manner in whic the contacts will successively engage the termi- ,nals of the lines to be tested as the shoe is progressively moved forward. For purposes of illustration sleeve contacts S1; S2 and S3 are shown.

the terminal S as indicated in Fig. 5, and later In Fig. 3 contact S1 is shown resting on a. terminal battery. This is in order to avoid a line capacity discharge into the test set causing a false trouble indication if the line is charged reversed to the test circuit battery. As pointed out heretofore the shoe is equipped with two springs I1 and Ia in order to prevent interference and false failure indications when it encounters intercepted subscribers lines. These springs are located beyond the T springs in such a position as to contact the sleeve terminals of the intercepting trunk terminals which form the first three rows on all H. I. D. F. terminal blocks.

to place a busy test condition on the sleeve terminals of all intercepting trunks encountered, thus preventing their interference with the test programs. As the shoe advances, contact S2 makes contact with the sleeve of the line and also with the spring S1. This is the condition illustrated in Fig. 4. This operation connects the ground 8 through contacts S1 and S2 to conductors I 4 and i5 and thence through the winding of relay 16 to ground. Accordingly, relay l6 will not operate at this time as it is shunted to ground. Contacts R2 and T2 make contact with the tip and ring terminals of the line which at this time have contacts R1 and T1 resting on them. This again is the condition illustrated in Fig. 4. Contact R2 is connected over conductor l I, contact of key K1, conductor l8 to a contact of relay l6. Contact T2 is connected over conductor I9, contact of key K1, conductor 20 to a contact of relay l6. As

relay I6 is not. operated at this time contacts R2 would then be connected over the sleeve of the line tocontact S2 and thence over conductors l4 These springs are 5 connected to 112 ohms of ground in the test box names:

- and-iwthe=-windlngtrre1cy 1sendiwculd cauee meme-w operate. j 'l lie operatie te {91537 18 will close'tthe fdllowirigscircuit' rem ground and rr ereiayi ,"coriductor 24, armature and cofitabtofielay l6, *conductor "I 8,

line;- 71f; due tdrault'y insulatiom afishort" circuit exists' between' the tip" and ring, or if' a' ground exists onthe ring side cfthe' l-lne;;a circuit-*will be completedover-theebove traced cireuitsth'roug-h 'thte'sbbaitteryandthe winding -of rfeleiy end will causethe' relaycite-operate. The operation of rcla'y 'zi wllr connect ground 26-' over itsannature and -contact,= over conductor21, 1eft hand armature' and contact of relay iii-conductor 28, and t-hence to battery through the-'w'inding of relay tuy and to "battery" through the filament of 'la'l-rnp 29. This w'illoperate the lamp-29 which wlll-give al -visual signal to iridicate 'thattrouble exists' -onthe line under test. The; relay 30* w ill lock up over conductor fi l to ground 52';-overthe iig'ht handicontactof'relay-M. The operation of ther'r'elay fill will cause a' groun'd to be-connected over-it's left-hand armature to conductor 33-and thence' ,to g'the buzzer- 34'. This will causethe buzzer torunction to give-an audible alarm that there'is; trouble on---'the' line -being' tested. I'he operationofrelaytwin-also-close the following circuit: ifromground, lett hand contactandarmature "of relay 30', "conductors "33, 34, 35, 36, winding; of stop =magnet'31; conductor 38*to battery'fill. Thiswill operate'the stopmagnet. "This .stopima-gnetfll might be provided with-=-a*-hori- .zont'al pin (not shown) which--'-wou=ld--' be driven between the terminals'toprevent -further%advanc'ement of the shoe.

"Upon" receiving? a "visual and an? audible-signal ithat, trouble exists on "the llne iarlduponoperation ,of thefstopmagnetifl; the test" man will throw the key "K1; This'wi'll" connect the'rte'sti-batterv 40 through the voltmeter '4 l "and thence over condu'ctoryfl, 43, contact of key Kigcon'du'ctor d,

conductor 11, contact"Rz to *th'e ring side or the line. Groundt ifi will'be connectedover-theconta'ctcor keyKz and-conductor"46,-' and thenceover the contact of-ikey'Kr' to "conductors 41' arid" "l 9-to 'c'onta'ct'Tzj and thence'to thetipgof-the' line, "A

iduelto; aj'short or a ground on" the ringside of the line, they test man will now 'operate" the kBY'Kz. .This will remove jthe ground' '45 from the tip side ,otfthe line. 511 the trouble. is due to a ground on ,the ring, side i of the 1; line the previously traced j circuit through the voltmeter 4 I willheheldclosed and the '2 functioning" or" the voltmeter will indicate ,fthat' the trouble 'is .due; to' a" ground on? the ringside of g'the'jline. If "the :voltni'eter fails to function when t the" key K2 is operated; the test malnvwillllknow; thatLthe trouble was-"caused" bra gfshort circuit between the ,tipend: ring conductors rbiifthelli Aiterr'the foregolngjcsequencei or event takes z-placect'theqtestman"will;nowioperatexthe*kef-Ka. I "The operation of this key wnr close thefollowing 15 65, to battery and ground i:'Ihis Mlloperatetrenix-mute tromegroundeandzbatteryalBefiindinazof relewazpconductcrilarconductori 0,1contact2cf k'eyKa onductor ittogr'oundail.'-i%'I!his:wi1lopei-+ ate therelay :2, r:.'rhez--cperationi:of relay: 32 will.

opem the previously traced locking-circuit tome-.- lay 30 -and: cause it to release. iJ'I he operation of relay- 32 will, overi itsi left ihand 'i armature and contact, plaee ai shunt' to ground 52': 'onz r'elays :l 6 and-cause lit to-release. Thei releasezof-relay I 6 opens' thepreviouslyfitraced: circuit for the relzw 23 whichwill-releaseand in turn release the relay 3ll ialnd the lampl 29. Therrelea'se ofzrelay 30 will" openthe previously- :traced circuits: for agthe buzzer-Wand :the stop magnet; 31. The' 'shoe-fis now at libertyto continue lite-advance across the line-terminals; I

' Gbviouslyidt no trouble had been encountered onthe' line; certain ot-theabove-described actions would-not have taken place such; for exampleia's the operation of r'e1ay 23 andthe 'subsequentop era'tion of-"the buzzer and stop' i magnet. As -the shoe"advances the contact S3 wou'ld come -into contactwith'the'contact Szwhichwo'uld be resting-on' the sleeve terminal of the line. i This would be the-condition lllustraited'in l igj 6. The relay I 6 which had previously been operated would-now-be releasedbecause it would be shunted'to-ground'll by theclosure of contact "S3 with contact 82'. "The release of relay 46 would open "the previously traced connection'from testbatt'ery' 22 to the-ring side'cfthe line' and the-previously traced-connecti'o'n from-ground 25 tothetip side of"'the"'line. As the 'shoe et'dvan'czes further-spring 84" makes contact with the sleeve terminal of thellne under test" and will connect ground 8 to the'sleeve of the line and operate'the cut-off relay 9 to remove battery-and ground'irom 'the tip and'rin-g side's'of the line. Following this action contactTs will m'tikecontat-Wlththe tip side ofthe line. The battery 1 lwill then-be connected through a resistance to conductor 52-and thence to contact Ta and to'the tipsideof the line. This battery'is placed onthe "linein-advance of the test in order to charee the tip to the same polarity'as the testing batterwto avoid a capacity charge or discharge from fal'sely operating the test apparatus. As the "shoeadvances further spring "S5 makes contact with the sleeve-ofthe line under test and *alsd'm'akes contact-with spring S4. T'Ihis wouldble the oondition illustrated inFig; 4. When spring Ssis'ln contact: with spring Srgroun'd 8"Wl11-be anplied throueh contacts S4 and S5 and thence over conductor 54;:conductorh'r5 and throu h the wind- :lng' of. relay? 53. 'I'his will place a grounded shunt onr'relay 53 andiit will not operate at this time. Contact 'Tvwill also make contact with" thetip terminal" of thef'line. Advancement of the shoe will :now': causespring- Sl to :break contact with the sleeve terminal of the line, shown in" Fig-.5; "'i'I'he iollowingmircuitcwill :thenfibe :closed; battery 2 l xswindin goof :cut -;offrelay 9; contactiss, conductors fi lzanclefiiswindingof; relay: 53 to:- ground. "This will operate relay: 53. v:The operation :of'-relay 153 'will' close th'e following circuit :2 from: ground and batteryzilizawinding 0f relay45T,-'conductor 58; lefthand contact: andrarmature' of relay 53;-conductor 59;contactaoi key K aconductorz 60; conductor fi I *centact Tito-the tinof the line. "If: a ground mow existson the tip .uof 'the' line the i closing 0f "this circuit Wills-operate therelay 51. The 'soperation wot-the relay e51 wiilv close thejwallowing circuit: "fIOmfgr-Ollnd 62;=-armature*and contacticf relay "51, conductor 63, right-hand 'contact :and arma ture err'e-lay 53, conductoretil9 winding; ottrelay layii5. The operation of relay 65 will apply a ground over its left-hand armature and contact to theipreviously traced circuit for the buzzer 3G and the stop magnet 31 and cause these two devices to function. The ground 62 applied by the operation of relay to the winding of relay 65 will also be applied to conductor 66 and will opcrate the lamp 61. Relay 65 will lock up over its armature and contact and conductor 68 to ground 52; The test man will now operate the key K4, This will connect the test battery All through the voltmeter 4i andthence over conductor 42, contact of key K4, conductor 60, conductor 6!, cone tact T4 to thetip of the line. The operation of key K4 will also disconnect the test battery. 56 from the tip of the line. If a ground eXists on the tip of the linethe voltmeter will now function to indicate the amount of leakage. After making his voltmeter measurements the test man will now operate to release key. This will close the previously traced clrcuit for the relay 32 and cause it to operate. The operation of relay 32 will open the previously traced locking circuit forrelay 65. The operation of relay 32 will place a shunt to ground 52 over its left-hand contact and armature on the winding of relay E3 and cause it to release. The release of relay 53 will open a previously traced circuit for the relay .5? and allow it to release. The release of relay 5? will open a previously traced circuit from ground 62 for the relay B5 and allow it to release. The release of relay 65 will extinguish the lamp 6? and will release the buzzer 34' and the stop magnet 31.

If no trouble was encountered on the tip of the line certain of the above described operations would not take place and theshoe in advancing further would cause contact S6 to come into contact with contact S5 which would still be resting on the sleeve of the line. This would be a condition similar to that illustratedin Fig. 6. This would place'a shunt'to ground 8 on the winding of relay '53 and cause it to release. The shoe would then advance further to test other lines embodiment in many and other Widely varied forms without departing from the spirit of the invention as defined by the appended claims. What is'olaimed is: 1. A device for testing telephone lines comprising a shoe having a set of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of a distributing frame where- V by the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve terminals of a line to be tested, means operative when certain of said contacts are on said line terminals for charging the line under test to a definite polarity, a testing circuit having a test battery 7 connected to one side thereof and a ground connected to the other side thereof, means operative when still other of said contacts are on said line terminals for connecting the battery side of said The si- 7 testcircuit to the ring terminal of the line under; test and for connecting the ground side of said test circuit to the tip terminal of the line under test, a relay in said test circuit adapted to be operated when said test circuit is completed by a short or a ground on the ring side of the line under test, :and stop mechanism controlled by the operation of said relay for preventing said shoe from being further moved over the line terminals. I V

2; A device for testing telephone lines comprising a shoe having a set of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve tore minals of a line to-be tested, means operativewhen certain of said contacts are on said line terminals forcharging the line under test toa definite polarity, a first testing circuit having a test battery connected to one side thereof and a ground connected to the other side thereof, means operative when still other of said contacts are on said line terminals for connecting the battery side of said test circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to the tip terminal of the line under test, an indicating de-' vice and stop mechanism adapted to be operated when said testing circuit is completed by a short or by a. ground on the ring side of the line under test, said stop mechanism being adapted toprevent said shoe from moving further over the line terminals, a'second testing circuit having a test battery and a voltmeter oonnectedto one side thereof anda ground connected to the other side thereof, a switching means for disconnect? ing said first mentioned testing circuit from the ring and tip terminals of the line under test and for connecting the battery and voltmeter side of said second testing circuit to the ring terminal of the line under test and for connecting the ground side of said second testing circuit to the tip terminal of the line under test, and a second switching means for disconnecting the ground side of said second testing circuit from the tip terminal of the line under test.

3. A device for testing telephone lines compris ing a shoe having a set of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of 'a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts willprogressively contact the tip, ring and sleeve terminals of a line to be tested, means operative when certain of said contacts are on said line terminals for charging the line under test to a definite polarity, a testing circuit having a test battery connected to one side thereof and a groundconnected to the other sidefthereof, means operative when 'still other of said contacts are on said line terminals for connecting the battery side of said test circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to thetip terminal of the line under test, an indicating device and stop mechanism adapted to be operated when said test circuit is completed by a short or by a ground on the ring side of the line under test, said (stop mechanism being adapted to prevent said shoe from moving further over the line terminals, a second testing circuit having a test battery and a voltmeterconnected to oneside-thereDf and-,.a grounds conn ted to the 7 other side thereofsxa 'switchinszmeans for disconnecting said firstmen tionedvtestingcircuit zfromgthe ring and tip terminals-ofthe line under test and forconnecting the: battery: and voltmeterside of. 1 said second testing: circuit to the ringterminabof therline under test and for connecting the groundside of said secondtesting: circuit to the tinterminalcf the line-lunder test, and. a 7 release ,key, which if operated: after :said switching meanshas been re,- stored to normal .-wi-l1- release said indicating. .device and said stop, mechanism and-will discon; nect saidi-flrst testinggcircuit [from said line under tests:

4. A device for testing telephone lines comprising a shoe having a set of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve terminals of a line to be tested, a testing circuit having a test battery connected to one side thereof and a ground connected to the other side thereof, means operative when certain of said contacts are on said line terminals for connecting the battery side of said test circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to the tip terminal of the line under test, a relay in said test circuit adapted to be operated when said test circuit is completed by a short or by a ground on the ring side of the line under test, responsive means controlled by the operation of said relay, means operative when still other of said contacts are on said line terminals for disconnecting said first testing circuit from the tip and ring terminals of the line under test, a second testing circuit having a test battery connected thereto, means operative when still other of said contacts are on said line terminals for connecting said second testing circuit to the tip terminal of the line under test, a relay in said second testing circuit adapted to be operated when said second testing circuit is completed by a ground on the tip side of the line under test, and responsive means controlled by the operation of said last mentioned relay.

5. A device for testing telephone lines comprising a, shoe having a set of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve terminals of a line to be tested, a testing circuit having a test battery connected to one side thereof and a ground connected to the other side thereof, means operative when certain of said contacts are on said line terminals for connecting the battery side of said test circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to the tip terminal of the line under test, a relay in said test circuit adapted to be operated when said test circuit is completed by a short or by a ground on the ring side of the line under test, responsive means controlled by the operation of said relay, means operative when still other of said contacts are on said line terminals for disconnecting said first testing circuit from the tip and ring terminals of the line under test, a second testing cirset 'of ring contacts and a set of tip contacts,

cuithaying at test battery: connected, thereto, means operativerwhen-stiltctherEofssaidvcontacts areon -saidg line, terminals, .for connecting, said second testing-circuit to the tip terminal 'of the line; under test acrelayjnfl said=second:-testing. circuit--, adapted to= be, operated when-said second testingtciiicuit completedby aground onthe' tip side of. ,the line under,-- ,test,-.responsive meansicontrolled, by operation of A said last: mentioned ..relay,, ,and rmeans operative when still other i of said contacts are on, said lineterminals fordisi.- connectingsaid,second testing gcircuit' ifromnthe tip terminallof the li'neunde'r test;

, 6; A- device for, testing ,telephone ilihesgcomprising agshoe having a set of sleevecontacts a said shoe being adapted to be slideably moved over the line terminals of a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve terminals of a line to be tested, means operative when certain of said contacts are on said line terminals for charging the line under test to a definite polarity, a testing circuit having a test battery connected to one side thereof and a ground connected to the other side thereof, means operative when still other of said contacts are on said line terminals for connecting the battery side of said test circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to the tip terminal of the line under test, a relay in said test circuit adapted to be operated when said test circuit is completed by a short or by a ground on the ring side of the line under test, responsive means controlled by the operation of said relay, means operative when still other of said contacts are on said line terminals for disconnecting said first testing set from the tip and ring terminals of the line under test, means operative when other of said contacts are on said line terminals for charging the tip side of the line under test to a definite polarity, a second testing circuit having a test battery connected thereto, means operative when still other of said contacts are on said line terminals for connecting said second testing circuit to the tip terminal of the line under test, a relay in said second testing circuit adapted to be operated when said second testing circuit is completed by a ground on the tip side of the line under test, responsive means controlled by the operation of said last mentioned relay, and means operative when still other of said contacts are on said line terminals for disconnecting said second testing set from the tip terminal of the line under test.

I. A device for testing telephone lines comprising a shoe having a set 'of sleeve contacts, a set of ring contacts and a set of tip contacts, said shoe being adapted to be slideably moved over the line terminals of a distributing frame whereby the several sleeve contacts, the several ring contacts and the several tip contacts will progressively contact the tip, ring and sleeve terminals of a line to be tested, a first testing circuit having a test battery connected to one side thereof and a ground connected to the other side thereof, means operative when certain of said contacts are on said line terminals for connecting the battery side of said testing circuit to the ring terminal of the line under test and for connecting the ground side of said testing circuit to the tip terminal of the line under test, a responsive device adapted to be operated when said first test- L6 ing-circuit is completed by a short or by a ground onthe ring s ldeof the line under test, a second testingcircuit having a test battery and a'voltmeter connected to one side thereof and a ground connectedto the other side thereof, a first switchingmeans for disconnecting said first testing circuit fromthe ringand tip terminals of the line under test and for connecting the battery and voltmeter side of said second testing circuit to the ring terminal of the line under test and'for connecting the ground side of said second testing circuit to the tip terminal of the line under test, asecond switching means for disconnecting the ground side of said second testing ,circuit from the .tip terminal of the line under test, a third 1 to be operated when-said third testing circuit completed by aground on the tip side-of the ;1in'e under test, a fourthtestingcircuit having'atest battery and a voltmeter connected thereto and a third switching means for disconnectingsaid third testing circuit from the tip terminal of the line under test and for connecting said fourth testing circuit to saidtip terminal. 2

' FRAN" K JESS CANNON GEORGE ELLIS GO'ODWIN. 

